TY  - JOUR
AU  - Luković, Jelena
AU  - Chiang, John C. H.
AU  - Blagojević, Dragan
AU  - Sekulić, Aleksandar
PY  - 2021
UR  - https://gery.gef.bg.ac.rs/handle/123456789/1088
AB  - Californian hydroclimate is strongly seasonal and prone to severe water shortages. Recent changes in climate trends have induced shifts in seasonality, thus exacerbating droughts, wildfires, and adverse water shortage effects on the environment and economy. Previous studies have examined the timing of the seasonal cycle shifts mainly as temperature driven earlier onset of the spring season. In this paper, we address quantitative changes in the onset, amounts, and termination of the precipitation season over the past 6 decades, as well as the large-scale atmospheric circulation underpinning the seasonal cycle changes. We discover that the onset of the rainy season has been progressively delayed since the 1960s, and as a result the precipitation season has become shorter and sharper in California. The progressively later onset of the rainy season is shown to be related to the summer circulation pattern extending into autumn across the North Pacific, in particular, a delay in the strengthening of the Aleutian Low and later southward displacement of the North Pacific westerlies. Plain Language Summary The rainy season over California is projected to show a distinct sharpening of the mean seasonal cycle, with winter precipitation increasing, and both autumn and spring precipitation decreasing. Our analysis of the past 6 decades of data for California suggests autumn decrease is already underway. A delayed start of the rainy season of 27 days since 1960s can exacerbate seasonal droughts and prolong the wildfire season. This delay occurs due to a number of conditions that controls precipitation: the summer circulation pattern has been extending throughout November across the North Pacific, and the wintertime strengthening of the Aleutian Low is delayed. Accordingly, the southward migration of the North Pacific jet stream as well as extratropical storm tracks, which marks the start of the California rainy season, are delayed. More work, using climate models, will be needed to provide a better understanding of atmospheric conditions across the North America and the North Pacific. However, our findings provide observational evidence for the projected rainfall change over California and inform ongoing discussion about the drying/wetting tendencies of the rainy season in California.
PB  - Amer Geophysical Union, Washington
T2  - Geophysical Research Letters
T1  - A Later Onset of the Rainy Season in California
VL  - 48
IS  - 4
DO  - 10.1029/2020GL090350
UR  - https://hdl.handle.net/21.15107/rcub_gery_1088
ER  - 

@article{
author = "Luković, Jelena and Chiang, John C. H. and Blagojević, Dragan and Sekulić, Aleksandar",
year = "2021",
abstract = "Californian hydroclimate is strongly seasonal and prone to severe water shortages. Recent changes in climate trends have induced shifts in seasonality, thus exacerbating droughts, wildfires, and adverse water shortage effects on the environment and economy. Previous studies have examined the timing of the seasonal cycle shifts mainly as temperature driven earlier onset of the spring season. In this paper, we address quantitative changes in the onset, amounts, and termination of the precipitation season over the past 6 decades, as well as the large-scale atmospheric circulation underpinning the seasonal cycle changes. We discover that the onset of the rainy season has been progressively delayed since the 1960s, and as a result the precipitation season has become shorter and sharper in California. The progressively later onset of the rainy season is shown to be related to the summer circulation pattern extending into autumn across the North Pacific, in particular, a delay in the strengthening of the Aleutian Low and later southward displacement of the North Pacific westerlies. Plain Language Summary The rainy season over California is projected to show a distinct sharpening of the mean seasonal cycle, with winter precipitation increasing, and both autumn and spring precipitation decreasing. Our analysis of the past 6 decades of data for California suggests autumn decrease is already underway. A delayed start of the rainy season of 27 days since 1960s can exacerbate seasonal droughts and prolong the wildfire season. This delay occurs due to a number of conditions that controls precipitation: the summer circulation pattern has been extending throughout November across the North Pacific, and the wintertime strengthening of the Aleutian Low is delayed. Accordingly, the southward migration of the North Pacific jet stream as well as extratropical storm tracks, which marks the start of the California rainy season, are delayed. More work, using climate models, will be needed to provide a better understanding of atmospheric conditions across the North America and the North Pacific. However, our findings provide observational evidence for the projected rainfall change over California and inform ongoing discussion about the drying/wetting tendencies of the rainy season in California.",
publisher = "Amer Geophysical Union, Washington",
journal = "Geophysical Research Letters",
title = "A Later Onset of the Rainy Season in California",
volume = "48",
number = "4",
doi = "10.1029/2020GL090350",
url = "https://hdl.handle.net/21.15107/rcub_gery_1088"
}

Luković, J., Chiang, J. C. H., Blagojević, D.,& Sekulić, A.. (2021). A Later Onset of the Rainy Season in California. in Geophysical Research Letters
Amer Geophysical Union, Washington., 48(4).
https://doi.org/10.1029/2020GL090350
https://hdl.handle.net/21.15107/rcub_gery_1088

Luković J, Chiang JCH, Blagojević D, Sekulić A. A Later Onset of the Rainy Season in California. in Geophysical Research Letters. 2021;48(4).
doi:10.1029/2020GL090350
https://hdl.handle.net/21.15107/rcub_gery_1088 .

Luković, Jelena, Chiang, John C. H., Blagojević, Dragan, Sekulić, Aleksandar, "A Later Onset of the Rainy Season in California" in Geophysical Research Letters, 48, no. 4 (2021),
https://doi.org/10.1029/2020GL090350 .,
https://hdl.handle.net/21.15107/rcub_gery_1088 .